Hybrid vehicle propulsion apparatus

ABSTRACT

A motor generator has a rotor directly coupled to a crankshaft and a stator disposed around the rotor. A shield plate is disposed between coils of the stator and an internal combustion engine. A first partition and a second partition are disposed between the coils and a flywheel positioned adjacent to a clutch mechanism.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a hybrid vehicle propulsionapparatus comprising an internal combustion engine having an outputshaft and a motor generator coupled directly to the output shaft.

[0003] 2. Description of the Related Art

[0004] There has been proposed a hybrid vehicle having an internalcombustion engine for generating propulsive forces by combustinggasoline and a motor generator which can be operated as an electricgenerator for regenerating electric energy and an electric motor forgenerating propulsive forces with electric energy to assist propulsiveforces produced by the internal combustion engine. The propulsive forcesproduced by the internal combustion engine and the electric motor arecombined as required to propel the vehicle. For details, referenceshould be made to Japanese laid-open patent publication No. 9-156388.

[0005] A flywheel is usually connected to the crankshaft of the internalcombustion engine for smoothing and stabilizing the rotation of theinternal combustion engine. With the motor generator coupled to thecrankshaft, since the rotation of a rotor, which is relatively heavy, ofthe motor generator tends to affect the rotation of the crankshaft, itis preferable to position the motor generator as closely to thecrankshaft as possible. Positioning the motor generator as closely tothe crankshaft as possible is effective to increase the rigidity of themotor generator.

[0006] However, the motor generator that is located closely to theinternal combustion engine poses a problem in that leakage currents andleakage fluxes from coils of the motor generator influence the internalcombustion engine which is made of metal, adversely affecting therotation of the crankshaft.

[0007] On a manual-transmission hybrid vehicle, it is necessary toposition a clutch mechanism between the internal combustion engine andthe transmission or between the motor generator and the transmission. Ifthe clutch mechanism is disposed closely to the motor generator, thenmetal particles produced by the clutch mechanism may be liable to enterthe motor generator, adversely affect propulsive forces generated by themotor generator. Specifically, if metal particles contained in anabrasive powder produced when the friction plates of the clutchmechanism are engaged and disengaged are attracted to the magnets of themotor generator, then the metal particles are magnetized and generatesmagnetic fields, which then adversely affect the electromotive forces orpropulsive forces that are generated. If the metal particles enterbetween the rotor and stator of the motor generator, then they are aptto increase the resistance to the rotation of the rotor, therebyadversely affecting the propulsive forces that are generated.

SUMMARY OF THE INVENTION

[0008] It is a general object of the present invention to provide ahybrid vehicle propulsion apparatus which has a motor generator disposedclosely to an internal combustion engine for allowing a crankshaft torotate in good conditions and preventing the internal combustion enginefrom being adversely affected by leakage currents and leakage fluxesfrom coils of the motor generator.

[0009] A major object of the present invention is to provide a hybridvehicle propulsion apparatus which is effective to prevent an internalcombustion engine from being adversely affected by leakage currents andleakage fluxes from coils of a motor generator, and which is relativelycompact.

[0010] Another object of the present invention is to provide a hybridvehicle propulsion apparatus which is effective to prevent leakagecurrents and leakage fluxes from coils of a motor generator fromadversely affecting a flywheel, a clutch mechanism, a transmission,etc., and which is relatively compact.

[0011] Still another object of the present invention is to provide ahybrid vehicle propulsion apparatus which is free of adverse effects dueto leakage currents and leakage fluxes from coils of a motor generator,and which is of relatively high rigidity.

[0012] Yet still another object of the present invention is to provide ahybrid vehicle propulsion apparatus which prevents metal particlescontained in an abrasive powder produced by a clutch mechanism fromentering a motor generator for thereby maintaining a desired level ofperformance of a motor generator.

[0013] The above and other objects, features, and advantages of thepresent invention will become more apparent from the followingdescription when taken in conjunction with the accompanying drawings inwhich preferred embodiments of the present invention are shown by way ofillustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a schematic plan view, partly in block form, of a hybridvehicle which incorporates a hybrid vehicle propulsion apparatusaccording to an embodiment of the present invention;

[0015]FIG. 2 is a perspective view of the hybrid vehicle propulsionapparatus;

[0016]FIG. 3 is a side elevational view of the hybrid vehicle propulsionapparatus;

[0017]FIG. 4 is a vertical cross-sectional view of the hybrid vehiclepropulsion apparatus;

[0018]FIG. 5 is an elevational view, partly cut away, of an end of aninternal combustion engine as viewed from a motor generator of thehybrid vehicle propulsion apparatus;

[0019]FIG. 6 is an elevational view of an end of the motor generator asviewed from a transmission of the hybrid vehicle propulsion apparatus;

[0020]FIG. 7 is an enlarged fragmentary cross-sectional view of themotor generator and a clutch mechanism of the hybrid vehicle propulsionapparatus;

[0021]FIG. 8 is an enlarged fragmentary cross-sectional view of anothershield plate;

[0022]FIG. 9 is an enlarged fragmentary cross-sectional view of stillanother shield plate;

[0023]FIG. 10 is an enlarged fragmentary cross-sectional view of yetstill another shield plate;

[0024]FIG. 11 is an elevational view, partly cut away, of an end of amotor generator as viewed from an internal combustion engine of a hybridvehicle propulsion apparatus according to another embodiment of thepresent invention; and

[0025]FIG. 12 is a vertical cross-sectional view of a hybrid vehiclepropulsion apparatus according to still another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026]FIG. 1 schematically shows in plan a hybrid vehicle V whichincorporates a hybrid vehicle propulsion apparatus according to anembodiment of the present invention.

[0027] As shown in FIG. 1, the hybrid vehicle V has an internalcombustion engine E for generating propulsive forces by combustinggasoline, a motor generator M which can be operated as an electricgenerator for regenerating electric energy and an electric motor forgenerating propulsive forces with electric energy to assist propulsiveforces produced by the internal combustion engine E, a clutch mechanismC, and also to a transmission T for selecting and transmitting thepropulsive forces to a drive axle 10.

[0028] The motor generator M is controlled by a motor drive circuit 12which is connected to a first energy storage unit 13 comprising acapacitor, for example, for supplying and storing high-voltage electricenergy, and a downverter 14 that is connected to a second energy storageunit 15 for storing electric energy. The hybrid vehicle V also has amanagement control circuit 16 connected to a motor control circuit 17for controlling the motor generator M through the motor drive circuit12, and also to an engine control circuit 18 for controlling theinternal combustion engine E.

[0029] The internal combustion engine E, the motor generator M, theclutch mechanism C, and the transmission T will be described below.

[0030]FIGS. 2 through 4 show the hybrid vehicle propulsion apparatuswhich is designed for use on a manual-transmission hybrid vehicle. Theinternal combustion engine E, which is a three-cylinder engine,comprises an oil pan 22, a cylinder block 24, and a cylinder head 26with a head cover 27 mounted on the top thereof. The oil pan 22 and thecylinder block 24 are joined to each other through a plurality ofjournal bearings 30 a-30 d, 32 a-32 d of a crankshaft 28. The crankshaft28 comprises a plurality of journals 34 a-34 d, a plurality of crankpins36 a-36 c, and a plurality of counterweights 38 a-38 f. The journals 34a-34 d are rotatably supported by the journal bearings 30 a-30 d, 32a-32 d. Connecting rods 40 a-40 c have respective ends operativelycoupled to the crankpins 36 a-36 c, respectively. Pistons 44 a-44 c areconnected to respective other ends of the connecting rods 40 a-40 c forsliding displacement in and along cylinders 42 a-42 d that are definedin the cylinder block 24.

[0031] The motor generator M and the clutch mechanism C are accommodatedin a housing 46 which is joined to an end of the internal combustionengine E.

[0032]FIG. 5 shows an end of the internal combustion engine E as viewedfrom the motor generator M. FIG. 6 shows an end of the motor generator Mas viewed from the transmission T. The housing 46 has a plurality ofattachment holes 47 defined in its outer circumference for passagetherethrough of mounting bolts for fastening the housing 46 to theinternal combustion engine E, and a plurality of holes 49 defined in itsouter circumference for passage therethrough of knock pins forpositioning the housing 46 and the internal combustion engine E withrespect to each other.

[0033] The motor generator M comprises a circular rotor 48 and adoughnut-shaped stator 50 disposed around the circular rotor 48. Asshown in FIG. 4, the rotor 48 is directly fixed to an end of thecrankshaft 28 by a bolt 56. The rotor 48 has a plurality of fins 58, 60on its opposite end faces, and a plurality of magnets 62, serving asalternate N and S poles, disposed on an outer circumferential surfacethereof.

[0034] The stator 50 comprises a circular array of coil units 64 (seeFIG. 5) each comprising a coil 70 wound around a core 66 made of aplurality of laminated metal sheets and guided by a cross-sectionallychannel-shaped guide 68. The stator 50 is fixed to the end surface ofthe internal combustion engine E by an attachment 72 disposed around thecoil units 64.

[0035] The guides 68 have circular grooves 74, 76 defined in radiallyouter and inner regions of the stator 50, as shown in FIG. 7. Threeelectrically conductive connection rings 78 a, 78 b, 78 c are stackedand mounted in the groove 74. Each of the connection rings 78 a, 78 b,78 c has an insulating layer coated on its surface, and is connected toevery third coil 70 for energizing the coils 70 with alternatingcurrents in three phases.

[0036] A disk-shaped shield plate 80 is mounted on the end of the stator50 which faces the internal combustion engine E for preventing magneticleakage from the motor generator M to the internal combustion engine E.The shield plate 80 is fixed to an attachment 72 (see FIG. 5) and hasridges 82, 84 disposed on respective outer and inner circumferentialportions thereof and engaging in the respective grooves 74, 76. Theridge 82 engaging in the groove 74 serves to press and position theconnection rings 78 a, 78 b, 78 c in the groove 74. The shield plate 80has a connector 86 projecting radially outwardly and supporting threeterminals 88 a, 88 b, 88 c projecting radially outwardly from therespective connection rings 78 a, 78 b, 78 c. The terminals 88 a, 88 b,88 c are connected to respective terminals 92 a, 92 b, 92 c extendingfrom a connector 90 (see FIG. 4) mounted on the housing 40.

[0037] If the shield plate 80 is to serve as an electrically insulatingplate, then it may be made of a synthetic resin or SUS (stainless steel)coated with an insulating layer of synthetic resin, fluorine or thelike. If the shield plate 80 is to serve as a magnetically insulatingplate, then it may be made of a metallic material.

[0038] The shield plate 80 may be fastened at its radially outer edge tothe cylinder block 24 by mounting bolts B, as shown in FIG. 8, or may befastened at its radially inner edge to the cylinder block 24 by mountingbolts B, as shown in FIG. 9. Further alternatively, as shown in FIG. 10,the shield plate 80 may have its radially outer edge bent axially towardthe housing 46 and fastened to the cylinder block 24 by mounting boltsB. According to still another alternative, the shield plate 80 may befastened to the rotor 48, rather than the stator 50.

[0039] A first doughnut-shaped partition 94 fixed to the housing 46 isdisposed on a side of the stator 50 which faces the transmission T. Thefirst partition 94 serves as a shield and has a radially inner regioncurved toward the transmission T. The first partition 94 supports aposition sensor 96 for detecting the angular position of the rotor 48with respect to the stator 50. A signal wire from the position sensor 96extends out of the housing 46 through a wire outlet hole 51 (see FIG. 6)defined in the housing 46.

[0040] A disk-shaped flywheel 100 is positioned with respect to therotor 48 by a positioning pin 99 and fastened to the rotor 48 by a bolt98 (see FIG. 4) oriented from the transmission T toward the motorgenerator M. The flywheel 100 has a ring gear 106 on an outercircumferential edge thereof which is held in mesh with a drive gear 104of the stator motor 102. As shown in FIG. 7, a drive plate 107 and asecond doughnut-shaped partition 108 are fixed to a surface of theflywheel 100 which faces the motor generator M. The second partition 108has a radially inner region curved toward the first partition 94 andradially overlapping the first partition 94. The starter motor 102 ismounted on an outer surface of a transmission case 137 of thetransmission T by mounting bolts B (see FIG. 3).

[0041] Each of the first and second partitions 94, 108 may comprise asynthetic resin plate or a thin SP plate (iron plate), or an SP platecoated with a layer of synthetic resin.

[0042] The drive plate 107 has a hole (not shown) defined therein inradially aligned relation to the position sensor 96. The angularposition of the drive plate 107 which rotates with the rotor 48 can bedetected by the position sensor 96 which detects the hole in the driveplate 107. The magnets 62 on the rotor 48 and the hole in the driveplate 107 are positioned relatively to each other by the positioning pin99 which engages both the rotor 48 and the flywheel 100.

[0043] The clutch mechanism C has a friction disk 112 mounted on asurface of the flywheel 100 which faces the transmission T. The frictiondisk 112 comprises a boss 116 with splines on its inner circumferentialsurface, a plate 120 extending radially outwardly of the boss 116through torsion springs 118, and friction plates 112 a, 112 b joined torespective opposite surfaces of the plate 120.

[0044] A pressure plate 124 is positioned on the friction plate 122 b ofthe friction disk 112. A diaphragm spring 130 is held by a wire spring128 on a housing 126 fixed to the flywheel 100. The diaphragm spring 130has an outer circumferential region disposed on one side of the pressureplate 124 which faces the transmission T. A piston 132 is disposed onone side of an inner outer circumferential region of the diaphragmspring 130 which faces the transmission T. The piston 132 is disposedaround a boss 134 on a transmission case 137 which is positionedcoaxially with the boss 116 of the friction disk 112. The piston 132 canbe displaced along the boss 134 by a hydraulic mechanism (not shown) topress the diaphragm spring 130. The transmission T has a shaft 136extending through the bosses 134, 116 and having an end engaging thesplines of the boss 116.

[0045] Operation and advantages of the hybrid vehicle propulsionapparatus thus constructed will be described below.

[0046] It is assumed that the hybrid vehicle V is propelled by theinternal combustion engine E. When the starter motor 102 is energized,the flywheel 100 is rotated by the drive gear 104 and the ring gear 106,rotating the rotor 48 to crank the internal combustion engine E.Gasoline is supplied from the cylinder head 26 into the cylinders 42 a,42 b, 42 c and ignited in the cylinders 42 a, 42 b, 42 c to displace thepistons 44 a, 44 b, 44 c in the respective cylinders 42 a, 42 b, 42 cfor thereby rotating the crankshaft 28. When rotated, the crankshaft 28rotates the rotor 48 of the motor generator M and the flywheel 100.

[0047] The driver of the hybrid vehicle V selects a suitable gearposition with the transmission T and makes an action to engage theclutch mechanism C. The piston 132 of the clutch mechanism C isdisplaced in a direction away from the diaphragm spring 130. Thediaphragm spring 130 is displaced to follow the piston 132, causing theouter circumferential edge thereof to press the pressure plate 124. As aresult, the friction plates 122 a, 122 b of the friction disk 112 issandwiched between the pressure plate 124 and the flywheel 100,whereupon the transmission T and the internal combustion engine E areconnected to each other through the rotor 48 of the motor generator M.

[0048] When the internal combustion engine E and the transmission T areconnected to each other by the clutch mechanism C, propulsive forcesfrom the internal combustion engine E are transmitted from the internalcombustion engine E through the transmission T to the drive axle 10 (seeFIG. 1), thereby propelling the hybrid vehicle V. Because the rotor 48of the motor generator M which is relatively heavy is directly coupledto the crankshaft 28, a relatively smooth and stable rotational powerflow is transmitted from the internal combustion engine E to thetransmission T.

[0049] It is now assumed that the hybrid vehicle V is propelled by themotor generator M. The first energy storage unit 13 stores electricenergy which has been generated in a regenerative mode by the motorgenerator M when the internal combustion engine E is decelerated oridles. When the electric energy stored in the first energy storage unit13 is supplied through the motor drive circuit 12 to the coils 70 of themotor generator M, the coils 70 generates a magnetic field to rotate therotor 48 and the flywheel 100. The rotation of the flywheel 100 istransmitted as propulsive forces through the clutch mechanism C and thetransmission T to the drive axle 10, thereby propelling the hybridvehicle V. The propulsive forces from the motor generator M can begenerated as assistive forces for propulsive forces from the internalcombustion engine E at the same time the propulsive forces are producedby the internal combustion engine E.

[0050] When the driver makes an action to disengages the clutchmechanism C, the piston 132 is displaced toward the internal combustionengine E, moving the outer circumferential edge of the diaphragm spring130 away from the pressure plate 124. The friction plates 122 a, 122 bare released from the gripping action by the pressure plate 124 and theflywheel 100, thus disconnecting the internal combustion engine E or themotor generator M from the transmission T.

[0051] When currents and magnetic fluxes leak from the coils 70 towardthe internal combustion engine E at the time the coils 70 are energized,since the cylinder block 24 is made of metal, the currents from thecoils 70 would tend to flow in the cylinder block 24 and the magneticfluxes from the coils 70 would tend to magnetize the cylinder block 24,thereby adversely affecting the operation of the pistons 44 a-44 c.

[0052] According to the illustrated embodiment, the shield plate 80disposed between the internal combustion engine E and the motorgenerator M is effective to block the currents and the magnetic fluxesfrom the coils 70 against leakage toward the internal combustion engineE. Therefore, the pistons 44 a-44 c will not be adversely affected bythe current leakage from the coils 70 and will not be magnetized by themagnetic flux leakage from the coils 70, so that the operation of thepistons 44 a-44 c will not suffer trouble. As a result, the operation ofthe internal combustion engine E will not be adversely affected. Becausethe motor generator M can be positioned closely to the internalcombustion engine E, the crankshaft 28 can rotate smoothly and stably,the motor generator M can be of increased rigidity, and the hybridvehicle propulsion apparatus can be compact as a whole.

[0053] The first partition 94 is positioned as a shield between themotor generator M and the flywheel 100. Therefore, no current andmagnetic flux leakage occurs from the coils 70 toward the flywheel 100.Therefore, the flywheel 100 will rotate smoothly without trouble.

[0054] In the illustrated embodiment, the motor generator M, theflywheel 100, and the transmission T are successively connected to theinternal combustion engine E. Since the structure by which the clutchmechanism C is attached to the flywheel 100 is not limited by the motorgenerator M, it is possible to employ a conventional attachmentstructure for the successive connection of the motor generator M, theflywheel 100, and the transmission T.

[0055] The first partition 94 also serves as a blocking member forblocking metal particles produced by the friction plates 122 a, 122 b ofthe friction disk 112 against entry into the motor generator M.

[0056] Specifically, with the internal combustion engine E or the motorgenerator M connected to the transmission T by the clutch mechanism C,metal particles produced by the friction plates 122 a, 122 b are firstblocked by the second partition 108 whose radially inner region iscurved toward the motor generator M and then by the first partition 94whose radially inner region is curved toward the flywheel 100.Furthermore, an air flow caused by the fins 60 on one of the oppositeend faces of the rotor 48 which is rotating is also effective to blockmetal particles against entry into the motor generator M. Consequently,the motor generator M is kept under good conditions without beingaffected by metal particles from the clutch mechanism C. The fins 58, 60are also effective to dissipate heat from the motor generator M as wellas to block metal particles against entry into the motor generator M.

[0057]FIG. 11 shows a motor generator M′ as viewed from an internalcombustion engine of a hybrid vehicle propulsion apparatus according toanother embodiment of the present invention. Those parts shown in FIG.11 which are identical to those shown in FIG. 5 are denoted by identicalreference characters, and will not be described in detail below.

[0058] The motor generator M′ has coil units 48 whose coils 68 have coilends connected directly to connectors 138 a, 138 b, 138 c which areconnected to the connector 90 mounted on the housing 46. An insulatingplate 140 is attached to the end of the housing 46 which faces theinternal combustion engine E, and covers the connectors 138 a, 138 b,138 c to insulate the connectors 138 a, 138 b, 138 c where the coil endsof the coils 68 are exposed.

[0059] The first partition 94 and the second partition 108 are disposedbetween the motor generator M′ and the clutch mechanism C for blockingmetal particles from the clutch mechanism C against entry into the motorgenerator M′.

[0060]FIG. 12 shows a hybrid vehicle propulsion apparatus according tostill another embodiment of the present invention. The hybrid vehiclepropulsion apparatus is designed for use on an automatic-transmissionhybrid vehicle. Those parts of the hybrid vehicle propulsion apparatusshown in FIG. 10 which are identical to those shown in FIG. 4 aredenoted by identical reference characters, and will not be described indetail below.

[0061] A flywheel mechanism F is disposed between the motor generator Mand an automatic transmission T′. The flywheel mechanism F is coupled tothe rotor 48 of the motor generator M by a joint plate 150 on which adrive plate 152 is mounted. The flywheel mechanism F includes a primaryflywheel 156 having a ring gear 154 on its outer circumferential edgeand connected to the joint plate 150. The flywheel mechanism F also hasa secondary flywheel 158 disposed parallel to the primary flywheel 156.The secondary flywheel 158 has a central boss 160 having splines engagedby the shaft 136 of the transmission T′. The primary flywheel 156 issupported on the boss 160 by a bearing 162, and is connected to thesecondary flywheel 158 by torsion springs 164.

[0062] In operation, after the starter motor 102 has cranked theinternal combustion engine E, the rotor 48 of the motor generator Mrotates to rotate the primary flywheel 156. The rotation of the primaryflywheel 156 is transmitted through the torsion springs 164 to thesecondary flywheel 158, whose rotation is then transmitted through theshaft 136 to the transmission T′. Depending on the rotational speed ofthe shaft 136, the transmission T′ actuates an automatic transmissionmechanism (not shown) thereby to rotate the drive axle 10.

[0063] The shield plate 80 and the first partition 94 block currents andmagnetic fluxes from the coils 70 of the motor generator M against entryinto the internal combustion engine E and the flywheel mechanism F.Consequently, the cylinder block 24, the primary wheel 156, and thesecondary wheel 158 are prevented from being subject to unwantedcurrents which would otherwise tend to flow therein, and also from beingundesirably magnetized. As a result, the crankshaft 28 can rotate stablyand smoothly.

[0064] Although certain preferred embodiments of the present inventionhave been shown and described in detail, it-should be understood thatvarious changes and modifications may be made therein without departingfrom the scope of the appended claims.

What is claimed is:
 1. A hybrid vehicle propulsion apparatus on a hybridvehicle having a drive axle coupled thereto, comprising: an internalcombustion engine for generating propulsive forces, said internalcombustion engine having an output shaft; a motor generator forgenerating propulsive forces, said motor generator having a rotordirectly coupled to said output shaft of the internal combustion engine;a transmission for transmitting the propulsive forces from said internalcombustion engine and said motor generator to said drive axle; and ashield member disposed between said internal combustion engine and saidmotor generator, for blocking currents and/magnetic fluxes leaking fromsaid motor generator.
 2. A hybrid vehicle propulsion apparatus accordingto claim 1, wherein said motor generator has a stator, said shieldmember being mounted on said stator.
 3. A hybrid vehicle propulsionapparatus according to claim 2, wherein said motor generator has coilsenergizable by currents from a connector, said shield member beingmounted on said connector.
 4. A hybrid vehicle propulsion apparatusaccording to claim 2, wherein said motor generator has coils connectedto connection rings, said shield member having a ridge by which saidcoils are fixed to said stator through said connection rings.
 5. Ahybrid vehicle propulsion apparatus according to claim 1, wherein saidshield member is mounted on said internal combustion engine.
 6. A hybridvehicle propulsion apparatus according to claim 1, wherein said motorgenerator has a stator, further comprising a flywheel disposed betweensaid motor generator and said transmission and coupled to said rotor,said shield member being disposed between said internal combustionengine and said stator and between said stator and said flywheel.
 7. Ahybrid vehicle propulsion apparatus according to claim 1, wherein saidmotor generator has a stator, further comprising a clutch mechanismdisposed between said motor generator and said transmission, forselectively transmitting rotation of said rotor to said transmission,said shield member being disposed between said internal combustionengine and said stator and between said stator and said clutchmechanism.
 8. A hybrid vehicle propulsion apparatus according to claim1, wherein said shield member comprises an electrically insulatingplate.
 9. A hybrid vehicle propulsion apparatus according to claim 1,wherein said shield member comprises a magnetically insulating plate.10. A hybrid vehicle propulsion apparatus on a hybrid vehicle having atransmission and a drive axle coupled thereto, comprising: an internalcombustion engine for generating propulsive forces; a motor generatorfor generating propulsive forces; a clutch mechanism disposed adjacentto said motor generator, for selectively transmitting the propulsiveforces from said internal combustion engine and said motor generator tothe transmission; and blocking means disposed between said motorgenerator and said clutch mechanism, for blocking an abrasive powderproduced by said clutch mechanism against entry into said motorgenerator.
 11. A hybrid vehicle propulsion apparatus according to claim10, wherein said motor generator has a stator and a rotor, said blockingmeans comprising: a first partition fixed to said stator; a secondpartition fixed to said rotor; said first partition and said secondpartition overlapping each other.
 12. A hybrid vehicle propulsionapparatus according to claim11, further comprising a flywheel coupled tosaid rotor, said second partition being fixed to said flywheel.
 13. Ahybrid vehicle propulsion apparatus according to claim 10, wherein saidmotor generator has a rotor having fins on a surface thereof which facessaid blocking means.